v 2.8.0.0|TortoiseGit
TortoiseGit, a Windows Shell Interface to Git, is based on TortoiseSVN. TortoiseGit does not require integration with a particular IDE, such as Visual Studio or Eclipse. It can be used with any development tool you choose and with any file. TortoiseGit's main interface will be through the context menu in a Windows Explorer interface.
These are the key features:
TortoiseGit was developed under the GPL. It is completely free to anyone, even in a commercial environment. You can also download the source code, which is available for free.
TortoiseGit gives you information like committing, showing logs and diffing two versions, creating branches, tags and creating patches, as well as regular tasks.